Electric pressing iron



prll 20, 1943. S WALLACE 2,36,907

ELECTRIC PREssING IRON y Filed July 11. 1939 3 sheets-sheet 1 mh mbQmmwm@ whim@ www @Q SMN 9@ m MQ n@ S h Q Q .c m

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April 20, 1943. s. WALLACE ELECTRIC PRESSING IRON 5 sheets-Sheet 2 FiledJuly l1, 1939 INVENTOR.

April 20, 1943. s. WALLACE ELECTRIC PRESSING IRON 3 Sheelgs-Sheet 3Filed July 11. 1939 Patented Apr. 20, 1943 UNITED STATES PATENT OFFICEvELECTRIC PRESSING IRON Stanley Wallace, Chicago, Ill.

Application July 11, 1939, Serial No. 283,860

Z Claims.

The present invention relates in general to electric pressing irons, andmore in particular to an iron o! this character which is provided withmeans for generating steam which is injected into the goods while theiron is in use. The main object of the invention is to provide a new andimproved steam iron.

In some respects the steam iron disclosed herein may be considered as animprovement on the iron shown in my copending application, Ser. No.143,031, filed May 17, 1937.

The inventionincludes a considerable number of improvements whichcooperate in producing a steam iron which is entirely safe, free fromtrouble, and more satisfactory to use than steam irons heretoforeavailable. The invention and the various features thereof will bedescribed in detail hereinafter, reference being had to the accompanyingdrawings, in which:

Fig. 1 is a sectional view of the complete steam iron, taken on the lineI-l, Fig. 2;

Fig. 2 is a section through the boiler, taken on 'the une 2 2, Fig. i;

Fig. 3 is partly a top view and partly a section of the sole plate, thesection being on the line 3 3, Fig. 1;

Fig. 4 is a section through the terminal housing taken on the line 4-I,Fig. 1;

Fig. 5 is a section through the Water tank and water control valve.taken on the line 5 5, Fig. 1;

Fig. 6 shows a modification and is a side view of the back part of theiron, with a part of the water tank in section to show a different formof water control valve mechanism;

Fig. 'l shows another modication, and is a section through a part of theboiler and the Water control valve; and

Fig. 8 shows a modified form o cap which may be used for the water tank,in case a continuous supply of water to the tank is desirable.

' Referring to the drawings, the sole plate 2, Figs. 1 and 3, maybesomewhat similar in construction to the one shown in my co-pendingapplication. It' has a recess 3 extending from the toe along both sidesto receive the lower edge of the cover. On the upper side of the soleplate there is a recess 4, in which the thermostatic control mechanismis mounted, as will be described presently. The reference numeral 5indicates a channel constituting a steam passage, the shape of which isclearly shown in Fig. 3. Outlets such as 6 extend from the steam passageto the face of the iron.

The 'boiler lis shown in Figs. 1 and 2. It isa one-piece casting, andhas a main steam-generating cavity 8, which may be filled with copperwool or similar material. Access to the cavity 8 is had through twoopenings at the top which are normally closed by threaded plugs I3 andI4. Partitions 9 and I0 extend from opposite sides part way across thecavity 8, and the latter partition is enlarged at lI to provide room forthe opening I2 in which the shaft |38 of the adjusting device for thethermostatic control mechanism is located. Near the forward end of theboiler a hole is drilled up from the bottom and is tapped to receive thethreaded tubular member I5. The lower end of member I5 lies in theopening i6 leading to the steam passage 5. A gasket 24 surrounds memberI5 and is compressed between the boiler and sole plate, where itprevents the leakage of steam.

The boiler l is secured to the sole plate 2 by means of a machine screwIl in front and by two machine screws such as i8, Fig. 1, at the rear.The latter screws pass down `through holes I9 and 20, Fig. 2, in theboiler, and are threaded into tapped holes 2i and 22, Fig. 3, in thesole plate.

The heating element 23 is clamped between the sole plate 2 and theboiler l. This element is of any suitable and known construction.

The rear part of the boiler, through which the screws I8 pass, is ofreduced thickness, as seen from Fig. l. This part oi the boilercomprises two sections 50 and 5I which are joined at the rear by atransversely-extending solid section 52. This construction provides alarge opening 53 through which pass the electrical connections to thethermostatic control mechanism. The sections 50 and 5I are hollow, beingprovided with channels 54 and 55. respectively, which communicate withthe main boiler cavity. The transverse section 52 drops down sharply atthe rear of the sole plate 2, as seen in Fig. 1, and has arearwardly-extending section 56. rI'he part 56 merges into the twocorner members 5l and 5B which are of slightly increased thickness andare rounded off at the rear, as seen in Fig. 2. The construction justdescribed is of utility in connecting the boiler with the water tank, aswill be explained presently.

The boiler is concealed beneath a cover 60, which is cast integrallywith the water tank 6I. The shape of this casting can be seen from Figs.1, 4, and 5, also Fig. 6. The cover portion conforms generally to theshape of the main part of the boiler. It is substantially dat on top,with slightly sloping sides, and is brought to a point in front. Thelower edge of the cover ts in the groove 3 of the sole plate 2. Abovethe rear part of the boiler the cover rises at an angle of about 70degrees and merges into the water tank. The tank lies to the rear of andpartly above the level of the boiler, as seen in Fig. 1. The forwardpart of the tank extends over the rear depressed portion of the boilerand is recessed in front, as seen in Fig. 4, to provide a housing forthe terminal strip.

The combined cover and tank casting is as-r sembled to the boiler andsole plate, as shown in Fig. 1, and is secured in place by means of twoscrews 62 and 63, which pass through the cover part and are threadedinto the boiler, and also by means of two large hollow screws or studs|54 and 65, which pass through the rearwardlyprojecting members 51 and58 of the boiler and are threaded into the bottom of the tank.

There are two passages leading from the water tank to the boiler, onefor the admission of water and the other for equalizing the pressurebetween the boiler and the space above the water level in the tank.These passages extend through the hollow screws 64 and 65.

Describing the pressure-equalizing passage,

Y there is an opening 66 drilled slantingly upward through theoverhanging part 52 of the boiler to tap the channel 55. This opening isplugged by a tapered screw 68. Another drilled opening 61 connects theopening 66 with the annular space surrounding the shank or unthreadedportion of the hollow screw 64. The latter is crossdrilled at 1| toafford a communication between the annular space referred to and thehollow interior of the screw, in which is tightly fitted the tube 12.This tube may be made of soft copper and is flexible enough so that thescrew 64 can be inserted and tightened up without difficulty with thetube in place. 'I'hus it will be seen that a continuous passage isprovided from channel 55 by way of drilled openings 66 and 61, thehollow screw 64 (cross-drilled as explained) and the tube 12 to thespace above the water level in the tank. Leakage is prevented by agasket inserted between the tank and part 58 of the boiler and anothergasket 69 beneath the head of screw 64.

The water passage extends through the hollow screw 65, and communicateswith the channel '54 of the boiler. From the screw 65 to the channel 54the water passage is exactly the same as the pressure-equalizing passagejust described, and includes the drilled openings 66' and 61', shown indotted lines in Fig. 2. From the screw 65 in the direction ofthe tank,the Water passage includes a manually-controlled shuto' valve 16, Fig.5, and an automatic shutoff valve 84, Fig. 1.

The manually controlled valve is located in a rounded shoulder 13, Figs.1 and 5, formed in the wall of the tank. In this shoulder a slopingopening 14 is drilled from the outside and is tapped to receive thethreaded portion 18 of the valve 16, the tapered end of which lies inthe ne opening which connects the opening 14 with the space above theend of the hollow screw 65. The opening 14 is counter-bored to a largediameter near the top and is tapped to receive the packing gland 11. Bymeans of the latter the packing 19 is compressed around the shank ofvalve 16`to prevent leakage. The valve 'i6 is rotated by means of knob80. By turning this knob in a clockwise direction, the tapered end ofthe valve may be advanced to completely close the opening 15. Turningthe knob in the opposite direction will back off the valve and open itto any desired extent.

The automatic shutoff valve is centrally located in the bottom of thetank, and is shown in Fig. 1. There is a downwardly-projecting annularrim 83 on the outside of the bottom wall of the tank. which is bored outto receive the disk 9|. This disk is provided with a. centralupwardly-extending cylindrical member 85, which is threaded tightly into-a tapped opening in the bottom of the tank. vThe member has a centralopening therein through which passes the valve stem 86, the said openingbeing faced oil on top to provide a seat for the valve 84. The valvestem 66 has a threaded connection with a stud which is riveted at thecenter of the diaphragm 81. This diaphragm is clamped between the disk9| and the closure member 89, the latter having a short threadedcylindrical portion which enters the tapped interior wall of the annularrim 63. A gasket is provided above and below the diaphragm to preventleakage. The coil Spring 88 normally is under a certain amount ofcompression, pressing inwardly on the diaphragm 81. Valve 84 is normallyopen. The vent 90 maintains the lower side of the diaphragm atatmospheric pressure.

A connection between the automatic shutoil.' valve and the manuallycontrolled valve is established by means of a drilled opening 82 whichpasses lengthwise through a raised rib 8| on the inside of the bottomwall of the tank. This rib extends from the shoulder 13 diagonallytoward the center of the tank where'it merges into the annular rim 83.The opening 82 connects with the space 81 above the disk 0| and at theother end it taps the opening 14 at a point which is a short distanceabove the opening 15. The rib 8| is seen clear in Figs. 1 and 4.

The path for the ow of water from the tank to the boiler may now betraced by way of valve 84, Fig. 1, valve stem opening in 85 to spaceabove diaphragm 81, drilled openings in disk 6| near the base of 65,space 81', drilled opening 82, space in opening 14, Fig. 5J valve 16,crossdrilled hollow screw 65, and openings 61' and 66', Fig. 2, to thechannel 54 leading into the main boiler cavity. This path can be closedby valve 16, under control of the operator, and may also be closed byvalve 84 responsive to an excessive boiler pressure, as will beexplained in described the operation of the iron.

The water.tank is filled from the top through an opening which isnormally closed by a cap |00. The cap is provided with a gasket so thatthe opening is sealed with the cap in place.

'I'he handle |02 may bemade of Wood or of some compositionmaterial'which is a good heat insulator. It is supported at the'rear ona tapered member |0| which projects forward from the upper part of thewater tank, and at the front on a bracket |06 which is secured to thecover by screw 62. The handle is in two parts, the main part |02 and arecessed forward part or forecap |03, which are clamped together and tothe bracket |06 and member |0| by means of a long bolt |04. This bolt isthreaded into a tapped hole drilled in member |0| and when tightened upholds the parts firmly in place. The recessed forwardpart |03 of thehandle partly encloses a bell cranklever ||0 which is pivoted at |01 onan ear forming part of bracket |06. Arm i 09 of the lever serves tocontrol the steam valve 34. The pin or stud |08 on the other arm ofasiduo? the lever projects through a slotted opening in the side ofhandle member |03 and carries a button or knob I II, Fig. 5,4by means ofwhich the'lever is operated.

The construction of the steam valve may now fbe explained. This valve islocated at the forward Aend of the boiler, as shown clearly in Fig. 1,in a recess which is formed in the solid toe of the boiler by drillingoperations. This recess overlaps the drilled recess for the head ofscrew |1. The valve includes a main body portion 21, the lower end 28 ofwhich is of reduced diameter and is threaded into the boiler. The member21 is enlarged at 26 and has a hexagonal head 25 by means of which itmay be screwed tightly in place. A gasket is interposed beneath theenlarged rim 26 to prevent leakage. The annular space surrounding themember 21 is connected with the boiler cavity by means o f a drilledhole 35. At the bottom of the recess in which the threaded portion 23 islocated a sloping hole 36 is drilled to the interior of the tubularmember |5.

The body 21 of the valve has a longitudinal bore to receive the valvestem 33, having a valve 34 at the lower end thereof. Leakage around thevalve stem is prevented by suitable packing which is compressed by thegland 3|. The valve is held closed by a coil spring 30, which istensioned between the outside face of gland 3| and' the nut 23 threadedon the end ofthe valve stem. This nut affords a means for adjusting thespring tension. The valve stem 33 is of reduced diameter toward thelower end, providing a steam passage which is connected with the spacesurrounding the valve body 21 by cross-drilling the latter at 32.

The steam valve is opened by operating the knob I I on pin |08, whichrotates the bell crank lever on its pivot |01 and depresses the valvestem 33 against the tension of spring 30. When the valve is open, steamcan pass from the boiler to the sole plate by way of opening 35, annularspace surrounding 21, cross-drilling 32 in 21, annular space surroundinglower portion of valve stem,valve 34, opening 36, and tubular member Ito the channel 5 in the sole plate.

It will be noted at this point that the steam valve is so arranged as toact as a safety valve. Steam pressure in the boiler tends to open thevalve and if an excess of pressure is built up the valve will openautomatically, allowing steam to escape into the sole plate until thepressure is relieved. The pressure at which the valve opens depends onthe tension of spring 30, which can be adjusted by means of nut 29, aspreviously mentioned.

ed inwardly-projecting shoulder |4I, seen in Fig. 5. The two conductorsof the cord are secured under terminal screws and |26.

The thermostatic control mechanism is mounted on a plate |42, Fig. 1,which is secured at the bottom ofthe recess 4 in the sole plate by meansof screws |36 and |31. The control mechanism comprises a bi-metallicelement |34, and contact springs |23 and |30, all of which are se- Theelectrical connections for the iron will now be described briefly. Thatportion of the front wall of the water tank which lies above the coveris given a U-shaped formation, as seen particularly in Fig. 4, to form ahousing for the terminal strip |20, said housing having side walls |2Iand |23 and the rear wall |22. The housing projects rearwardly into thetank, as seen in Figs. 4 and 5. The side walls |2I and |23 have verticalslots in which the terminal strip |20 is retained. 'I'his terminal stripis of suitable insulating material, The housing is lined with a sheet ofinsulating material (not shown) to guard against accidental shortcircuits, and is closed in front by the plate |24.

The cord for supplying current to the iron enters the housing from theright side through an opening |40, Fig. 1, which is formed in theroundcured to plate |42 by means of screw |35. I'he contact springs aresuitably insulated and are provided with contacts |32 and |33 which arenormally in engagement. When the bi-metallic element |34 becomes heated,the free end moves upward due to bending of the element and engages theend of screw |43, thereby raising the end of spring |29 to separatecontact |32 from contact |33. Screw |43 is adjustable. 'I'he workingadjustment during use of the iron is accomplished by means of the lever|40, secured to the shaft |38. This shaft has a cam |38 nea;` the lowerend which raises or lowers contact |33 responsive to rotation of shaft|33 in one direction or the other, and thus determines the temperatureat which the contacts |32 and |33 are separated by the element |34.

The upper contact spring |29 extends to the rear and is bent upward,passing through the opening 53 in the boiler to the terminal strip whereit is secured under screw |26. The other contact spring |30 is connectedto one end of the winding of the heating element 23. The other end ofthe heating winding is comiected to a metallic strip |28, which extendsupward along the back of the terminal strip |20 and is bent over aroundthe top of the strip and retained under screw |25. By the describedarrangement the heating element 23 is connected in series with contacts|32 and |33.

The operation of the iron will now be described.

VThe knob should rst be turned down to close the water valve 18, afterwhich the cap |00 can be removed and the tank illled with water. The capis then replaced and screwed down tightly. The cord may then be pluggedinto a convenient receptacle and the iron will begin to heat up. Thethermostatic control knob |40 should be set forl the desired heat value,depending on the type of material to be ironed.

When the iron has become thoroughly heated, the water valve 16 may beopened and water4 will ow from the tank to the boiler by way of the pathdescribed. Since the `boiler is hot, steam will be formed at once, butthe Water continues to flow into the boiler, due to thepressure-equalizing-passage including tube 12, which maintains thepressure above the water in the tank equal to the back pressure at thewater passage. The opening 15 is rather small and when the valve isfully open. allows only enough water to enter the boiler to provide forthe maximum steam requirements. The size of the opening can be reducedby adjustment of the valve.

If the steam valve remains closed, the pressure in the boiler will risegradually, and since the same pressure exists in the tank, the valve 04will close before long. The spring B6 may be so designed that the valvewill close at a pressure of about five pounds. The closure of valve 84shuts off the supply of Water to the boiler, which tends to prevent anexcessive rise in boiler pressure and avoids the waste of water in casethere is some delay in beginning work with the iron.

When the ironing operation begins, the operator presses forward on knob|I| with his thumb,

which actuates lever I to open the steam valve 34, and steam begins toiiow through the valve into channel 5 in the sole plate and out throughthe openings 6 in the toe of the iron. On entering channel 5 the steamflows through the sole plate to the rear and then returns to the toe ofthe iron before passing out through the openings 6. The passage of thesteam through the hot sole plate insures that only dry steam will bedelivered to the material being ironed. The steam valve may be operatedintermittently or may be held open for substantial intervals asrequired. As the steam is used, the pressure in the boiler falls,whereupon the valve 84 opens to admit more water. During continuousironing operations this valve will remain open most of the time, but ifany suspension of operations occurs, the valve responds to the resultingrise in steam pressure and shutsof the water. This makes it unnecessaryto close the manually operated valve '|6 until the ironing is completed,even if the work is interrupted from time to time.

As previously mentioned, the steam Valve is so constructed that it alsooperates as a safety valve. The valve is enabled to function in thismanner because the steam pressure inside the boiler tends to open thevalve against the tension of spring 30. This spring may be so adjustedthat the valve will open at a boiler pressure of about eight pounds.With this adjustment the valve ordinarily will not open automatically,because the automatic shutoif valve 84 cuts oi the water supply when thepressure reaches ve pounds. If anything should go wrong with the shutoifvalve, however, or if the heat adjustment is too high, the pressure mayincrease sufcientlyto open the steam valve. It will be seen, therefore,that the iron is entirely safe. The dual functioning steam valve isparticularly reliable in performing its function of a safety valvebecause it is in conthe steam valve permits the flow of steam along thechannel 5, which cools the sole plate somewhat and causes the element|34 to turn on the heat again sooner than would otherwise be thel case.Although the steam is hot it still has a somewhat lower temperature thanthe sole plate, so that the described effect will take place. The effectis greatly enhanced if the operation reaches the critical stage wheremoist steam begins to leave the boiler, indicating an imperative demandfor heat, which is met at once by the loss of heat matic shutoff valvein one structure, or, in other words, to simplify the iron by providinga dualpurpose valve which may be manually controlled and is alsocontrolled automatically responsive to a rise in boiler pressure.

The iron shown in Fig. 6 is the same as the one shown in Figs. 1 5,except that the manually controlled valve '|6 at the side of the tank,together with the shoulder '|3, is entirely omitted and is replaced by anew valve structure at the rear of the tank which incorporates both themanual and automatic control feature. 'Ihere are other minor changes inthe tank structure, which will be apparent. That part of the drawingFig. 6 which is shown in section is on the v line 6 6, Fig. 2.

' downwardlyis bored out to receive'the diaphragm tinuous use undermanual control and is always free and operative; or, at least, ifanything goes wrong'with it, the fact willv immediately become apparent.This overcomes the objection to a separate safety valve, which operatesvery infrequently, and may become stuck and remain that way without itscondition becoming known.

When the iron is to be put away, the cord is disconnected'and the wateris shut off at valve '|6 to prevent flooding of the boiler as thetemperature goes down. The tank need not be emptied.

The location of the channel 5in the sole plate is of special importance,particularly when working on certain fabrics, such as silk and rayon;which have to be ironed with a relatively low sole plate temperature,say about 225. This temperof the cup-shaped member I ature isconsiderably-below the temperature at which the heating element canmaintain the iron, and consequently the thermostatic control will comeinto play from time to time to shut off the heat. The bi-metallicelement |34 is located where it is affected by the sole platetemperature, which changes rather slowly due to the large mass of thematerial of which it is composed. It is desirable to accelerate thechange in temperature in the vicinity of the element |34, to give aquicker and more accurate control, and decrease the length of theintervals during which the'heat is off. thus avoiding any danger ofwater accumulating in the boiler. To this end the channel 5 is directedto the rear of the sole plate close alongside the recess in which thebi-metallic element |34 is located. At any time when the heat is Thebottom of the tank 6| is cast With a extending annular rim |50, which|54. The diaphragm |54 is clamped between two gaskets against theshoulder in annular rim |50 by means 52, which is attached to the rim|50 by means of several screws such as |5|. The member |52 is vented atthe center s'o that the space inside is at atmospheric pressure. A coilspring |53 is housed in member |52V and presses against the center ofthe diaphragm |54. The space |55 above the diaphragm is connected by adiagonal passage 82 with the space at the end of the hollow screw Justabove the center of the diaphragm |54 there is an opening drilledthrough the bottom of the tank. This opening is countersunk onthe-inside to form a seat for the valve |58. The valve is formed lat thelower end of the rod |51, which continues beyond the valve in the formof a stem |56 of reduced diameter the end of vmanually operated part ofthe valve comprises off and while the iron is in use, the opening of ashaft |6|, which is rotatable |63. The shaft IBI is threaded at itslower end in an abutment formed in the tank wall. The shaft issurrounded by packing, held in place by the gland |62. The upper section|60 of rod |51 enters a hole drilled in the end of shaft |6|.

When the valve |58 is open, water can ow from the tank through the valveinto the space |55 and thence by way of passage 82', hollow screw 65',the drilled openings shown, and the channel 54' to the main boilercavity. Spring |53 tends to oppose closing of the valve, and itsstrength may be suicient to prevent 'closing of by means of knob ed. 1Thel -bottom of the hole in shaft |6| will engage the end of extension|60, whereupon further rotation oi' the knob in the same direction willclose the valve. It will be seen therefore, that the valve structuredescribed comprises a valve which will respond automatically to apredetermined rise in boiler pressure to shut of! the water, which canbe adjusted by hand to vary the pressure to which the valve responds,and which can be closed by hand at any time. f

'I'he operation of the iron modified according to Fig. 6 is otherwisethe same as the operation oi' the main embodiment already described.

The modification disclosed in Fig. 'l has for its main object theprovision of a temperaturecontrolled water valve, adapted to replace themanually controlled valve such as i6. As an additional improvement thetemperature-controlled valve is also controlled by boiler pressure,which enables the automatic shutoff valve 04 to be omitted. Thus themodication about to be described comprises a dual-purpose water valvecontrolled in accordance with the temperature oi' the boiler and also inaccordance with the pressure in the boiler.

The valve is located at the rear of lthe boiler, just behind partition9, see Fig. 2, and in line with the channel 54 in therearwardly-extending leg 50. The channel 54 is, however, omitted, andthe casting is further modified to include a raised portion 2|3 on thefloor of the boiler cavity. The roof of the boiler is made considerablythicker at this point and is bored out from above to receive the ring203. This ring has a transversely-extending curved arm 206. Above thering 203 there is assembled a diaphragm 204, which is clamped in placebetween two gaskets by means of the threaded cup-shaped closure member2|4, the latter having a hexagonal head at the center by means of whichit can be screwed down tightly. The member 2|4 is drilled and tapped atthe center to receive the screw 2||. A spring 2|0 is tensioned betweenthis screw and the diaphragm 204.

On the lower side of the diaphragm there is secured a bimetallic element202 which may be shaped as shown in the drawings. The lower horizontalportion of the element 202 is perforated to admit the body of the valve209, and the stem of the valve passes up through an opening in arm 206.The valve is urged to its'seat by a light spring 205 secured to arm 206.The element 202 is normally under compression, the end of the elementbearing against the edge of the ledge 2|3.

The passage 200 is drilled out from the rear of the boiler and lsplugged at the end by means of a screw 20|. This passage connects withpassage 66 at the rear. The passage 200 extends forward past the centerof diaphragm 204, and is tapped by an opening drilled down through ledge2|3 from above. This opening is countersunk to provide a seat for valve209. The valve is normally held closed by gravity and by the spring 206.Screw 2| is an adjusting screw for varying the boiler pressure to whichthe valve is responsive and is accessible through an opening 2|2 in thecover 00'.

Describing the operation of this modification briefly, when the tank isiilled no water can pass to the boiler because the valve 209 is closed.When the iron is connected to a source of current, it begins to heat up,likewise the bi-metallic element 202, which gradually loses its tensionand eventually bends upward to raise the valve 209. The bi-metallicelement should preferably be arranged to open the valve responsive to a.temperature of about 215 degrees. When the water is first admitted, theparts will be cooled down somewhat, and the valve may close, but willsoon open again as the heating continues and the water is converted tosteam. The valve will therefore feed water to the boiler only at timeswhen the temperature is high enough to convert the water to steam andpositively prevents iiooding of the boiler with Water.

As in the case of the main embodiment of the invention, if the steam isnot discharged by opening the steam valve, the pressure in the boilerwill rise and eventually will exert a force on diaphragm 204, which issufficient to bend the diaphragm outwardly against the tension spring2|0. The adjustment of this spring may be such that a pressure of aboutfive pounds is required for operation, as in the previous case. Thehorizontal portion of the 'bi-metallic element 202 is now restingagainst the end of arm 206, holding valve 209 open, but when thediaphragm 204 rises it carries along the element 202, or attempts to doso, and the horizontal portion of the element acts about the end of thearm 206 as a fulcrum to close the valve. That is, the diaphragm raisesall that part of the bi-metallic element to the right of the fulcrum atthe end of arm 206 and consequently the end of the element to the leftof the fulorum point is lowered and the valve is closed. When theconsumption of steam begins the pressure Within the boiler falls, thediaphragm 204 returns to normal and the valve 209 is opened again,provided, of course, that the temperature has been maintained.

Referring now to Fig. 8, there is shown a cap which may be substitutedfor the cap |00 of Fig. 1 as a closure for the water tank. The modifiedform of cap comprises a main threaded body portion 250, having ahexagonal shoulder 252 by means of which it can be screwed tightly intothe tapped opening at the top of the tank. The body 250 has alongitudinal bore, in which is located a check valve in the form of aball 251, held in its seat by a light coil spring 258. A tube 25| isthreaded into the lower end of 250. At the upper end of the body member250 there is inserted a curved tube 255. This tube is provided with ashoulder 254, which is held against the end of 250,

with a gasket interposed, by means of a clamping nut 253. By looseningthis nut the tube 255 can be turned in any desired direction.

The reference character 256 indicates a rubber hose which leads to amain supply tank from which the water is fed to the tank in the iron bygravity. The height of the tank should be sufiicient to develop a headof about three pounds. When the water is turned on at the supply tank,the water will flow through the hose and valve 251 in the cap, iillingthe tank in the iron. Some time before the water level reaches the topof tube l2, however, the air in the tank and boiler will be compressedenough to build up a pressure which will stop the ilow of water, thesteam valve being closed. When water is admitted to the boiler, steamwill be generated which maintains the pressure.l ,As the iron is beingused the steam valve will be opened at intervals and at such times thepressure in the boiler and tank will fall far enough so that water canenter through valve 251. Thus the tank may be kept supplied with waterduring continuous use over long periods, which is especially desirablewhen the iron is in service in a laundry.

The cap shown in Fig. 8 is also desirable in the ordinary domestic useof the iron to facilitate refilling. Unless some care is taken inremoving the cap |00, Fig. 1, there is danger of burning by hot steam, adifliculty which is avoided by the modified form of cap, since it doesnot have to be removed. Removal of the cap is unnecessary because of thepassageway including the tube 25'5 and valve 251, through which watermay be introduced in any suitable or desired manner.

'Ihe invention having been described, that which is believed to be newand for which the protection of letters Patent is desired will bepointed out in the appended claims.

I claim:

1. In a steam iron, a sole plate, a boiler superimposed on said soleplate and secured thereto with a heating element between them, athermostatic device in said sole plate to control said heating element,,said device comprising a bimetallic strip disposed lengthwise of thesole plate, steam outlets in the face of the sole plate, avalve-controlled steam passage leading from the boiler to the sole plateat a point near the toe thereof, and a channel in the sole plate throughwhich the steam is conducted to the said outlets over a path whichextends rearwardly parallel and close adjacent to said device, wherebythe response of the device to a demand for heat is accelerated.

2. In a steam iron, a sole plate, a boiler superimposed on said soleplate and secured thereto with a heating element between them, athermostatic device in said sole plate to control said heating element,a steam passage leading from the boiler to the sole plate, a manuallycontrolled Valve in said passage, and a steam channel in the sole plateleading to outlets on the face thereof,'a partof said channel ahead ofthe said outlets being so related to the said device that in case moiststeam is admitted through said valve the evaporation of the water insaid moist steam will draw heat from the sole plate in the immediatevicinity of the device and accelerate the response thereof.

3. In a steam iron, a sole plate having a central recess therein for athermostatic device, a steam channel in said sole plate starting at apoint forward of said recess and extending in Atwo branches to the rearof the sole plate, said branches being located on opposite sides of saidrecess in good heat transfer relation to the device therein and afterreversing at the rear of the sole plate extending forward to the toe ofthe iron where they join, steam outlets adjacent the junction of saidbranches, a boiler superimposed on said sole plate, and a steam passageleading from the boiler to the channel and connecting therewith wherethe channel starts.

4. In a steam iron, a sole plate, a boiler superimposed on said soleplate, a heating element between the boiler and sole plate, a one-piecemeans for securing said tank to said extension,v

and means includingv passages in said extension for establishingcommunication between the boiler and tank.

5. In a steam iron, a sole plate and boiler in superimposed relation, aheating element common to said boiler and sole plate, a cover of castmaterial enclosing the boiler and heating element, a terminal strip formaking electrical connections to said element, and a water tank in therear' of and Vabove the boiler, said tank being cast integrally with thesaid cover and having a recess in the front thereof to form a housingfor said terminal strip.

6. In a steam iron, a sole plate, a boiler superimposed on said soleplate and having a solid extension in the rear thereof, a water` tanksupported on said extension and secured thereto by hollow screws, andpassageways connecting the interior of the boiler with the interior ofthe tank including said screws and holes drilled in said boilerextension.

7. In a steam iron which includes a boiler and a water tank, a waterpassage leading from the tank to the boiler, a normally closed valve insaid passage, means foi` heating said boiler, and means responsive tothe boiler temperature rising to a predetermined point for opening saidvalve.

8. In a steam iron which includes a boiler and a. Water tank, a waterpassage leading from the tank to the boiler, a normally closed valve insaid passage, and a thermostatic device including a bi-metallic stripfor opening said valve responsive to a predetermined boiler temperature.

9. In a steam iron which includes a boiler and a water tank, a, waterpassage leading from the tank to the boiler, a normally closed valve insaid passage, means for heating said boiler, means for opening saidvalve responsive to the boiler temperature rising to a predeterminedpoint, and means for closing said valve while the temperature remainsabove the opening point responsive to the pressure in the boilerincreasing to a predetermined extent.

10. In a steam iron, a boiler, a tank from which water is fed to theboiler automatically, means including a thermostatic device for startingthe feed of water responsive to a predetermined boiler temperature, andmeans for stop ping the feed responsive to a predetermined boilerpressure.

1l. In a steam iron, a boiler, a water tank, a passage leading from saidtank to said boiler, a second passage for maintaining thepressure abovethe water in said tank nequal to the boiler pressure, a valve in saidfirst passage, a ilegible diaphragm set in the wall of the boiler forcontrolling said valve, and means including said diaphragm for closingsaid valve responsive to the boiler pressure rising to a value whichexceeds the atmospheric pressure by a predetermined amount.

12. In a steam iron which includes a boiler and a tank for supplyingwater to the boiler,

a closure member for said tank, a passage ex-,

tending through said member for nlling the tank, and a check valve insaid passage.

13. In a steam iron, a sole plate, a boiler supen imposed-on said plate,a steam valve for controlling the ilow of steam from the boilerV to thesole plate, a cover for the boiler, a handle and means for securing itto the iron including a bracket attached to said cover, means forcontrolling said valve including a bell crank lever pivoted on saidbracket and located entirely in front thereof, a knob for actuating saidlever, and a detachable recessed fore cap for the handle partiallyenclosing said lever.

14. In a steam iron which includes a boiler and a water tank, a waterpassage leading from the tank to the boiler, a valve for controlling theflow of water through said passage, a thermostatic device for openingsaid valve to admit water to the boiler, a passage for communicatingboiler pressure to the tank, and means for closing said valve responsiveto the said pressure rising to a predetermined point above atmosphericpressure.

15. In a steam iron, a boiler, a sole plate, a passage for conveyingsteam from the boiler to the sole plate, a normally closed manuallycontrolled steam valve in said passage, a water tank, a passage forconveying water from said tank to said boiler, a water valve in saidlast mentioned passage, said water valve being closed when the iron iscold, means for heating the iron and boiler, temperature responsivemeans for opening said Water valve upon a predetermined temperaturerise, and means for automatically closing said water valve in responseto excessive boiler pressure due to continued closure of said steamvalve.

16. In a steam iron, a boiler, a sole plate, a

water tank, an automatic water valve for controlling the now of waterfrom the tank to the boiler, said valve being adjusted to shut oil thewater upon a predetermined rise in boiler pres'- sure, and an automaticvalve for controlling the :dow of steam from the boiler to the soleplate, said last mentioned valve being adjusted to open at apredetermined boiler pressure Which is greater than the pressurerequired to close said water valve.

1'7. In a steam iron, a boiler, a water tank for supplying water to saidboiler, means for heating said boiler to generate steam, means includinga lvalve for automatically shutting off the water supply to the boilerupon a predetermined rise in steam pressure, and thermostaticallycontrolled means for automatically effectlng closure of said valve whenthe heat is turned off to prevent ilooding the boiler.

i8. In a steam iron, a sole plate, a boiler, a water tank, a passage forconveying water from said tank to said boiler, a passage fortransmitting boiler pressure to said tank, a passage for conveying steamfrom the boiler to the sole plate of the iron, a steam valve in saidlast mentioned passage, a water supply pipe extending t said tank from awater supply source under pressure tending to deliver water to the tank,and a check valve operatively interposed betweenr said tank and thewater supply source for preventing a reverse flow of water in case theboiler pressure rises above the water-supply pressure due to failure toopen said steam valve.

19. In a steam iron which includes a boiler and a tank for supplyingwater to the boiler, said iron having a water passage extending from thetank to the boiler, a passage for communicating steam pressure in theboiler to the tank ata point above the level of water therein, a watersupply pipe for delivering Water to the tank under pressure, said pipeterminating inside the tank below the water level, and a check valve insaid pipe for preventing a reversal of water ow in case the steampressure rises higher than the water pressure. y

20. In a hand operated steam iron, a boiler and a water tank bothsupported on and movable with the rest of the iron, a waterpassage'leadi118 from the tank to the boiler, a valve in said passage,means for maintaining equal pressures in the boiler and tank independentof said passageway, a diaphragm forming part of the wall of saidpassageway and subject to the pressure of the water therein, such waterpressure being due to the steam pressure in the boiler acting on thewater in said passageway, and means whereby said diaphragm is operativeto eiIect closure of said valve in response t0 a predetermined pressureof the water in said passage.

21. In a steam iron adapted for to and fro manipulation by hand, aboiler and a water tank both supported on and forming part or the iron,the said boiler and tank being so arranged on the iron that the bottomof the tank cavity is approximately level with the bottom of the boilercavity, a passage leading from the tank to the boiler, means independentof said passage for maintaining equal pressures in the tank and boilerto permit the iiow of water through said passage by gravity, a valve forclosing said passage to stop the water flow, and means including adiaphragm responsive to the boiler pressure for controlling said valve.

22. In a hand manipulated steam iron, a boiler and a water tank bothsupported on and forming part of the iron, means for maintaining equalpressures in said tank and boiler, a passage for transferring water fromthe tank to the boiler by gravity, said passage including a waterretaining cavity which is below the level of both the boilerI and tankand hence is incapable ot draining into either the boiler or tank, avalve for closing the said passage, and means including a. diaphragm incontact with the water in said cavity and responsive to the pressure ofthe steam in said boiler transmitted to the said diaphragm through thewater in said cavity for operating said valve.

23. In a hand operated steam iron, a boiler and a Water tank securedtogether and movable as a unit with the remainder of the iron, said tankhaving a recess formed in the exterior bottom Wall thereof, a diaphragmclosing said recess, means including a valve for admitting water fromthe tank to said recess, a passage for conducting water from said recessto said boiler, and means whereby said diaphragm is adapted to effectclosure of said valve responsive to the pressure in said recesscommunicated thereto from the boiler via said passage.

24. In a steam iron, a sole plate, a boiler superimposed on said soleplate and secured thereto, a heating element between said boiler andsole plate, a one-piece casting comprising a water tank for supplyingwater` to the boiler and a cover enclosing said boiler and heatingelement, the cover portion of said casting having a rim which rests onthe sole plate and the tank portion of the casting having a partengaging a corresponding part of the boiler, means for establishingcommunication between the tank and boiler through said parts, and meansfor securing said casting to the boiler, including means for clampingsaid parts together.

25. In a steam iron, a sole plate, a boiler superimposed on said soleplate, a heating element between said boiler and sole plate, a cover ofcast material cooperating with said sole plate to enclose the boiler andheating element, a water tank cast integrally with said cover, said tankbeing located to the rear of the boiler and including a portion whichextends upwardly from the rearl of the cover portion o! the casting,said tank also including a portion cooperating with the boiler throughwhich communication between the boiler and tank is established, a handlefor the iron, and means for securing said .handle to the forward end ofsaid cover and to 5 said upwardly extending portion of said tank.

STANLEY WALLACE.

